Previous studies showed that an inflatable seatbelt system could better protect occupants subjected to frontal crash by reducing the head excursion, chest deflection, and cervical spine injury. The main reasons for these reductions are because the inflatable seatbelt system is designed to distribute the crash force over a wider area of the body and to reduce body forward displacement by tightening the belt during deployment of the seatbelt airbag. Small female occupants are considered vulnerable during vehicle collisions, but the vulnerability was not studied for the inflatable belt system. This study evaluated the impact response of small female and midsized male occupants using an inflatable seatbelt system and compared their biomechanical response and injury outcomes.

Frontal-impact sled tests were conducted with eight small female postmortem human subjects (PMHS) and four mid-size male PMHS using a generic inflatable seatbelt system. Occupant kinematics, sensor data, and injury outcome were analyzed and compared. These results correlate to the reported PMHS data during frontal impacts using the inflatable belt system. It was also observed that small females sustained more rib fractures than mid-sized males, which was likely due to their poor bone conditions.